There are a number of industrial plant installations where it is highly desirable to cover or fully enclose the pipes and particularly insulated pipes to protect them from corrosive, contaminating elements that might contribute to bacterial growth or dirt accumulation and the like. In many plant installations such as in meat packing plants, it is highly desirable to be able to periodically clean the covered pipe covering system using high pressure steam or the like. Tubular type pipe covering sections and the entire covering systems that hermetically seal fluid carrying pipes or insulated pipes in a plant have heretofore been provided for this purpose. The advantage of using curled tubular sections over flat sheets is that with thicker flat sheets there is difficulty in holding the overlapped edges together where with the curled tubular sections these overlapped edges hold firmly against one another. The practice then is to form a cold weld at the joint or seam using some form of adhesive.
In the U.S. Patent to Helling No. 3,560,287 there is described tubular covering sections made from blanks of thermoplastic material and in U.S. Patent to Helling No. 3,499,072 there are described apparatus and methods for forming such tubular pipe covering sections. In the apparatus and methods described in the latter Helling patent, it is the practice to heat the material between 175.degree. F and 190.degree. F and then simultaneously curl and cool the blanks. A significant difference between the practice of the Helling patent and the present invention is that in the present invention the initial heating is only to remove any memory, the curling is accomplished between a roller arrangement and then the blank is held in a wrapped form and heated to temperatures on the order of 120.degree. F and 150.degree. F for periods of time between about 12 and 24 hours. Under these circumstances the pre-heating is not critical and can be accomplished in an efficient relatively inexpensive manner and the curling is accomplished using a relatively simple roller arrangement.
Accordingly, it is a general object of the present invention to provide novel and improved methods for forming tubular pipe covering sections of a selected size from a sheet of elastomeric material.
Yet another object of the present invention is to provide a novel apparatus and methods of forming tubular pipe covering sections that does not require complex, expensive apparatus for the practice thereof.
Still a further object of this invention is to provide novel apparatus for forming generally tubular pipe covering sections that is reliable, relatively simple, easily operated and highly effective for producing relatively large quantities of different sizes of the product.
Another object of this invention is to provide novel apparatus for forming generally tubular pipe covering sections that will readily produce sections for a wide range of pipe diameters with a minimum of set up time.